#include <iostream>
#include <math.h>

using namespace std;

double gt(int n) {
	double kq = 1;
	if (n == 0) return kq;
	for (int i = 1; i <= n; i++) {
		kq = kq * i;
	}
	return kq;
}

int main() {
	float x, e = 0.00001;
	double tong = 0, s1 = 0, s2 = 0;
	int i = 0;
	cout<<"Nhap x: "; cin>>x;
	cout<<"Tim duoc e^"<<x<<" = ";
	do {
		s1 = s2;
		tong += pow(x, i) / gt(i);
		s2 = tong;
		i++;
	} while (fabs(s2 - s1) > e);
	cout<<s2;
	return 0;
}